1. Field of the Invention
The present disclosure relates to an image processing apparatus and an image processing method.
2. Description of the Related Art
In image processing apparatus such as an MFP (Multi Function Peripheral), an image scanning unit such as a scanner scans a document image and generates image data of the document image, and the image data can be outputted to a sheet by an image forming unit or transmitted by a facsimile communication unit.
Even if the document is a blank sheet (i.e. blank document) which has no characters, an ordinary image processing apparatus usually outputs the image data of the document image as is to a sheet or performs facsimile transmission of the image data to a recipient. Printing and facsimile transmission based on the image data of the blank document image rise problems such as waste of paper sheets for printing and confusion at the recipient.
Therefore, some techniques have been proposed to identify whether the document is a blank sheet or not on the basis of image data of the document image.
For example, a copy machine includes a performing unit which performs a copy action of a document image to a single side and/or double sides of a paper sheet, and a detecting unit which detects a blank side among double sides of the document sheet. This copy machine also includes an identifying unit which identifies whether the document sheet is printed on double sides, whether the document sheet is printed only on a single side, and whether double sides of the document sheet are blank on the basis of the detection results of the detecting unit, a control unit which controls the performing unit on the basis of the identification result of the identifying unit to perform a copy action totally unified to single-sided or double-sided, and an outputting unit which outputs the copied paper sheet. The control unit of this copy machine is characterized by canceling the copy action of the performing unit of a blank side in the document sheet. It is described that therefore, it is possible to cancel unnecessary copy action of a blank side in the document sheet.
Further, a facsimile machine scans and transmits plural sheets of a double sided document. This facsimile machine includes a blank page detecting unit which detects a blank page in image information of the scanned plural pages, a page arrangement processing unit which arranges residual pages except the blank pages detected by the blank page detecting unit among the plural pages in its page order, and a transmitting unit which transmits image information of plural pages arranged by the page arrangement processing unit on the basis of the arrangement result. It is described that image information of plural pages except blank pages arranged in the page order is transmitted and image information of plural pages except specified pages arranged in the page order is transmitted, and therefore, unnecessary transmission is not performed.
Further, an image processing apparatus includes an image scanning unit which optically scans image information on a document, an image processing unit which performs a predetermined image process for the image information scanned by the image scanning unit, and an image outputting unit which outputs the image information for which the image processing unit has been performed the image process to a sheet. This image processing apparatus also includes a blank sheet identifying area setting unit which sets a blank sheet identification area used for identifying whether the document is a blank document or not, a blank document identifying unit which obtains the image information corresponding to the blank sheet identification area from the image scanning unit and identifies whether the document is a blank document or not, and a control unit which controls the image processing unit and the image outputting unit to cancel the later image forming action if it is identified that the document is a blank document. It is described that therefore, image forming is not performed for an unnecessary blank document, it is possible to reduce an unnecessary sheet for the blank document and identify whether the document is a blank document or not in a shorter time than a time required to scan all areas of all the document, and moreover blank sheet identification is possible for the document more quickly than using a fixed blank sheet identification area set by a user.
Further a blank sheet identifying apparatus includes a first identifying unit which identifies whether a document put on a reading area is a blank sheet or not on the basis of a document signal corresponding to a scanned whole area of the scanning area, an effective image area setting unit which sets an effective image area cut out as a predetermined area at an edge area from the reading area if the first identifying unit identifies that the document is not a blank sheet, and a second identifying unit which identifies whether identifies whether the document is a blank sheet or not on the basis of an image signal corresponding to the effective image area. It is described that even if the first identifying unit identifies that the document is not a blank sheet, the second identifying unit performs additional identification except for a part in which identification error may occur, and therefore, it is possible to properly perform blank sheet identification.
However, image data which a user wants to identify a blank sheet is not limited to image data of a sheet of which the whole area is blank.
For example, a document has a punch hole in an edge part (e.g. left edge part). When a document image of the document is scanned, a dark circle mark of the punch hole appears in an edge part of the document image. Due to this dark mark, it is not identified that the document image is a whole blank sheet. In general, if a document has a punch hole in an edge part but content of the document is blank, it is better to identify that the document is a blank sheet and not to output the document.
Further, to detect a document which contains the punch hole as a blank sheet, for example, a binarization threshold value is set close to the density value of white, here “255”, so as to detect a pixel with a low density value of gray as a pixel with the density value of white. However, in such a manner, for example, an image of a pale character such as a character written with a pencil is binarized to an image with the density value of white, and therefore, in such a manner, the document may be erroneously detected as a blank sheet.
Further, although the technique of the aforementioned blank sheet identifying apparatus can limit the area for blank sheet identification to a predetermined area, this limit may result in a trouble.
For example, since the number of pages and a page number are recorded in an edge part, mainly, a bottom edge part, a document which contains only a page number may be detected as a blank sheet and not outputted. Consequently, if image data is read from plural documents which contain respective serial page numbers, the document detected as a blank sheet is missing and at the missing document the continuity of the page numbers is broken. Moreover, a page number is usually printed as a very small character, and therefore, even if an area which contains only a page number is included into a blank sheet detection area, since the number of pixels with the density value of black in its image is very small, the blank sheet detection is not avoided. Thus, the aforementioned techniques can not solve the aforementioned problems.